Somehow, I have a lot of free time on my hands, so I've been doing this system for the last three or four years: Watch at least the first episode of any really popular drama and any drama that has a unique poster.
If you don't like it, drop it! Don't waste your time on anything that's uninteresting for you, especially if it doesn't hook you in the first episode.
If you're not sure how you feel about it, continue watching a few more episodes to see if you really want to stick with it. While watching many shows, I've noticed that if I'm not excited to wait another week for it's release, I'm not going to finish it in the long run.
If you love it, continue watching! However, there's no pressure to finish a drama if you don't have the time, energy, or interest to keep watching. You can always read spoilers to see how the show progresses or watch edits of your favorite characters.
For the past 6 years, I've been watching shows while they're airing, and I have to say, it's a big commitment. I've watched maybe 5, 6, or even 7 ongoing shows in a week before, and while I had a bunch of time to spare, 10-14 hours of shows every week is a lot! Don't let your FOMO waste your time on something that doesn't make you happy.
I hope this helps!